Input Stream as an Object?

I am reading in a file using:

Code:

---

  JFileChooser fileopen = new JFileChooser();
        String Title = "Please select your matrix file";
        fileopen.setDialogTitle(Title);
        int ret = fileopen.showDialog(null, "Open file");

        if (ret == JFileChooser.APPROVE_OPTION) {
            file = fileopen.getSelectedFile();
        }
        try {
            FileInputStream fstream = new FileInputStream(file);
            // Get the object of DataInputStream
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String str;
//Iterate over each line in the file and get a count on the number of Rows. This will help determine the
//size of the LinkedListArray.
            while ((str = in.readLine()) != null) {
                Lines++;
            }
            in.close();
//We have to account for the matrix dimensions row, so remove a row.
            RowCount = Lines - 1;
        } catch (Exception e) {
            System.out.println(e.toString());
            System.exit(1);
    }

---

This is to get the number of rows in the file so I can initialize a LinkedListArray to its proper size. Later in my program, I create a new file input stream and read in lines from the same file again to actually do the processing. Is there a way that I can gather thee data from the file during the first process, and store it, so that the 2nd time I dont have to read the file again.

When you read the first time you can store in a collection such as arraylist or something.